/*
 * Copyright (c) 2018  STMicroelectronics – All rights reserved
 * The STMicroelectronics corporate logo is a trademark of STMicroelectronics
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice, this list of conditions
 *    and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright notice, this list of
 *    conditions and the following disclaimer in the documentation and/or other materials provided
 *    with the distribution.
 *
 * - Neither the name nor trademarks of STMicroelectronics International N.V. nor any other
 *    STMicroelectronics company nor the names of its contributors may be used to endorse or
 *    promote products derived from this software without specific prior written permission.
 *
 * - All of the icons, pictures, logos and other images that are provided with the source code
 *    in a directory whose title begins with st_images may only be used for internal purposes and
 *    shall not be redistributed to any third party or modified in any way.
 *
 * - Any redistributions in binary form shall not include the capability to display any of the
 *    icons, pictures, logos and other images that are provided with the source code in a directory
 *    whose title begins with st_images.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 */

package com.st.smartTag.nfc.smarTag

import com.st.smartTag.util.*

/**
 * struct containing the sampling memory status
 * [nextSamplePtr] offset where the next sample will be written
 * [sampleCounter] number of samples to read
 */
data class SamplePositionCell(val nextSamplePtr:Short,
                              val sampleCounter:Int)


/**
 * convert struct to be stored inside a nfc memory cell
 */
fun SamplePositionCell.pack():ByteArray{
    //*4 to convert from the rf memory address to the i2c memory address
    val last = (nextSamplePtr *4).toShort()
    val sampleCounterShort = sampleCounter.toShort()
    return byteArrayOf(
            sampleCounterShort.lsb(),
            sampleCounterShort.msb(),
            last.lsb(),
            last.msb())
}

/**
 * extract the SamplePositionCell from a nfc memory cell
 */
fun unpackSamplePosition(rawData:ByteArray): SamplePositionCell {

    val counter = rawData.leUShort //rawData[0],rawData[1]
    //*4 to convert from the i2c memory address to the RF memory address
    val last = (rawData.extractLeUShortFrom(2)/4).toShort() //rawData[1],rawData[2]
    return SamplePositionCell(nextSamplePtr = last,
            sampleCounter = counter)

}
